Dynamo-electric machine



Jury 25, 1939. s A Moss 2,167,487

DYNAMO-ELECTRIC MACHINE Filed July 31, 1937 lll Inventor: SemFord A; Moss;

Hl Attoney.

Patented July 25, 1939 Sanford A. Moss, Mass., assignor to Gen eral Electric Company, a corporation ofv New York Application July 31, 1937, Serial N0. 156,742 4 Claims. (Cl. 1 -252) My invention relates to improvements in dynamo-electric machines, and more particularly to an improved Ventilating system for such machines.`

5 An object of my invention is to provide an improved ventilating orl cooling system for dynamoelectric machines.

Another object of my invention is to provide an improved rotatable member construction for l dynamo-electric machines. f

Further objects and advantages of my invention will-become apparentl and my invention will be better understood from the following description referring to the accompanying drawing, and

l the features of noveltyi'which characterize my invention will be pointed out with particularity in the claims annexed to and forming part of this'specication.

Fora better understanding of my invention, 20 reference is-made to the accompanying drawing wherein Fig. 1 is a sectional view partly in eleva-v .30 II secured and connected together by a. plate- I2 extending peripherally` about the central portion of the machine. A Ventilating intake opening I3 is formed in the bottom end of the casing to f provide an inlet passage for cooling air into the 3:, interior of the machine, and auxiliary equipment comprising al transformer I4 and copper oxide rectiilers I4a are arranged over this intake open` ing I3 in the path of the cooling medium, and securedv by screws I5 to a base I5 forming the .m bottom plate of thestationary member frame or casing. The stationary member is provided with an annular supplementary frame, which yis formedof two'annular. members I1 and I8 se-v cured together by a plurality of axially extend- 4:, ing boltsy AIil'spaced apart by an annularA laminatedv permanent magnet core 28. 'I'he supplementaryframe comprising the annular members I1 and I8 is supported upon the end shields Iland Il by avplurallty of bosses 2| and 22 :.n formed on the end shields'lil and I I, respectively,

which engage annular anges 23 and 24 formed onthe annular elements I1` and I8, respectively. TwoA cbncentric radially extending laminated cores 25 and 26 are ysecured betweenplates 21 sa. and 28, and 23 and 38.' to the annular frames I1 annular `flanges 33 and 34.

and I8, respectively. The auxiliary annular frames I1 and I8, and the annular core members 20, 25, and 25, and the supporting plates 21, 28, 29, and 30 are formed of magnetic material and form the magnetic circuitof vthe `stationary 5 vmember of the dynamo-electric machine. A stationary armature winding 3i is arranged in slots formed around the linner periphery of the laminated cores 25 and 26, and the excitation of the dynamo-electric machine is provided by a ileld exciting winding 32 which extends vannularly about, and adjacent to theinner surface of the annular laminated'core 2li, and outside of the armature winding 3|. This field exciting winding 32 is secured in position by annular anges l5 33 and 34 formed on the auxiliary stationary frame members I1 and I8, and is energized by current rectified bythe rectiilers I4a from the armature winding.3|. The permanent magnet core provides the necessary excitation for the 20 build-up of the machine. 'I'he stationary member of the dynamoeelectricmachine is arranged so that it is essentially a scroll for an impeller vtype fanhaving the inlet-opening I3 in one end thereof-which communicates with annular passages between\the end shields I8 and II and the annular cores ,land 25, and-providedwith an exhaust scroll including' an annular s e formed between the annular laminated cores 25. and 25 and the eld exciting winding 32 and the Il Exhaust ports or 'openings 35 and 35 are formed inthe annular frames i1 and I8 respectively. Tapered. recesses 31 are formed in the annular laminated core 28 and cooperate with the exhaust openings 35 and. 38 36 to provide exhaust ports communicating with a plurality Aof'exhaust ports .or ,openings 38 formed in the cylindrical plate or casing I2. The rotatable'member of the dynamo-electric machine is .provided with a'shaft 33 supported by 40 bearings `4I| and 4I arranged in hubs 42 and 43 formed on the end shields Il and I I, respectively,

' and is' provided with a coupling member 44 secured to one end of the shaft and arranged to be driven by any suitable source oi power. The rc- 4I tatable member of the dynamo-electric machine comprises two similar umts arranged on eachA side of the central cooling air exhaust ,e. Each of these units is provided with a set of laminatedw salient pole pieces and 46 secured lo in angulaily displaced relation by a key 41m'- ranged in the. keyways. 48 and 43 of the pole pieces 45 and 48 respectively. In electrical apparatus, it is desirable to cool the core'of the apparatus, as the heating of' a` machine generally u is the limiting factor in determining its capacity, and in order to properly cool dynamo-electric machines, Various arrangements of Ventilating passages have been provided for conducting.a cooling medium through the machine. The Ventilating system of each rotatable member unit, that is, of each set of salient pole pieces, is constructed so that it is essentially a Ventilating impeller or fan. Each outer end of the rotatable member is provided with an annular plate 50 made of a high resistance aluminum alloy, or similar high resistance non-magnetic material, which will not affect the magnetic circuit of the machine and will not produce appreciable eddy current losses. Each of these annular platesy 50 is provided with axially extending curved Ventilating intake vanes 5l providing impellersurfaces arranged to direct a cooling medium over the salient pole pieces 45 and 46 into `a plurality of axially extending Ventilating passages 52 formed between adjacent pole pieces of each set of pole pieces. The outer peripheral edge of the annular plate 50 is formedwlth an axially extending annular flange or ring 53, and the inner side 54 of this ring is arranged in engagement with the outer edge 55 of the laminated pole pieces 45 and 46 and acts as a retaining ring for clamping andl supporting the outer endsof the laminated pole pieces in position. Furthermore, since no axial Ventilating passagesare formed through the salientpole pieces, the cooling medium which enters through the Ventilating openings formed between the curved intake vanes 5I, which are arranged adjacent the outer face of the salient pole pieces, is directed over this outer surface through a circumferentially extending passage between it and the inner edges 55 of the intake vanes 5I, into the axial Ventilating passages between the pole pieces, and thereby cools the pole pieces. The cooling air is exhausted from the rotatable member and blown into the annular passageformed in the stationary member between the cores 25 and 26 and out through the exhaust openings 38 in the casing by a fan arranged axially between the two sets of pole pieces 45 and 46 and provided with a plurality of impeller fan blades or exhaust vanes 51 arranged on the sides of the salient-pole pieces opposite the annular plates 5U. The fanI blades 51 extend axially in both directions from a central radially extending supporting body 58 which is formed with gradually curved surfaces 55 changing from an laxial surface at the base of the core to a radially extending surface at the outer edge of the core to direct the' axially flowing airoutwardly.l The portions 60 of the body 58 adjacent the axial Ventilating passages 52 between the salient pole'pieces 45 and 45 extend axially into engagement with the intermediate sections 6l` of the laminations joining the pole pieces and forming thebottom ofvv the axial Ventilating passages 52. The portions 6I of the body 58 adjacent the salient-pole pieces do not extend axially .as far as the inner side of the pole pieces and thereby provide a circumferentially extending Ventilating vpassage E2 between the base 6I' of the fan and the salient pole pieces through which coolner surfaces thereof. Since the pole pieces are Vangularly displacedr with respect to each other, I,the portions 60 of -the body 58 also are formed ina correspondingly angularly displaced relavt'on onopposite sides of the core. 'I'he outer raallyfextending edges 63 of the fan blades 57 are arranged in engagement with the outer edges on the inner sides of the laminated pole pieces for clamping and supporting them in position. Thus, the rotatable memberof the dynamo-electric machine is essentially an impeller fan with intake vanes, intermediate axial Ventilating passages, and exhaust vanes or blades, and the stationary member of the dynamo-electric machine is essentially a scroll having an intake opening and an annular passage for directing thev cooling air 26 and the Winding 3l, into the rotor intake vane passages to the rotor axial passages 52,` and out of the exhaust bladey passages into the annular Ventilating passage formedbetween the laminatedcores 25 and 26, about the field exciting winding 32 and the laminated core 20, and out through the exhaust ports or openings 38 in the c asing of the stationary member.

While I have illustratedv and described a particular embodiment of my invention, modifications thereof will occur to those skilled in the art.v I desireit to be understood, therefore, that my invention is not tobe limited to the particular arrangement disclosed, and I intend in the appended claims to cover all modificationsI which do not depart from the spirit and scope of my invention.

, What I claimas new and desire to secure by .arranged on said rotatablemember in communication with each outer end of said =rotatable member axial passages and arranged to provide` circumferentially extending l passages between v said salient pole pieces and adjacent vanes com- -n 'lunicating with said rotatablel member axial passages, and discharge vanes associated with saidv rotatable member and arranged intermediate said sets of salient pole pieces in communication with allof said Ventilating passages.l

2. A dynamo-electric machine having a stationary member and a rotatable member arranged to provide a Ventilating impeller fan for said dynamo-electric machine, sets of salient pole pieces on said rotatable member and axially extending Ventilating passages extending between said polepieces, said sets of salient polel pieces vbeing angularly displaced from each other, Ventilating passages through said stationary member, a plate 'having intake Ventilating vanes arranged adjacent each end of said rotatable. member to clamp said salient pole 'pieces thereto with said Ventilating vanes in communication with said rotatable member axial passages, and discharge vanes arranged intermediate said sets of salient pole pieces in communication with all of said Ventilating passages.

3, A dynamo-electric machine having a stationary Amember and a rotatable member ar-Y ranged to provide a Ventilating impeller i'an ior` curing' thereto said salient pole pieces, said clamping members having intake Ventilating Vanes arrangedto direct a Ventilating medium into each end of said rotatable member axial passages; and discharge vanes arranged intermediate said sets oi salient-pole pieces to direct 0 the Ventilating medium outwardly.

yLAdynamo-electric machinev having a stationary member provided with a casing having an intake opening, a plurality oi cores for said stationary member spaced apart to form an annular passage centrally o i said casing, said casing having an exhaust opening communicating with said annular passage, a rotatable member provided with salient pole pieces, axially extending Ventilating passages extending between said `salient pole pieces, intalte Ventilating impeller surfaces carried by. said rotatable member directing a Ventilating medium into said axial Ventilating passages and providing circumferential Ventilating passages extending between said 'salient pole pieces and adjacent impellers, and Ventilating discharge means associated withsaid 4rotatalaile member in communication with said v axially extending Ventilating passages for directing a Ventilating medium into said annular; passage to said exhaust opening -in said casing.

SANFORD A. MOSS.' 

